1. Field of the Invention
The present invention relates to security systems for preventing unauthorized access and/or use of certain machinery and/or equipment. More particularly, the present invention relates to preventing access and/or use of aircraft and potentially dangerous instruments.
2. Description of the Related Art
The tragic events that took place on Sep. 11, 2001 in the United States resulted in more than 3,000 lives lost because of the unauthorized hijacking of aircraft and the subsequent use of the aircraft as weapons to cause massive amounts of fatalities. Aircraft, as well as other common carriers (e.g. trains, buses, cruise ships, tractor trailers) are all necessary instruments of modern day life, yet if commandeered by terrorists, can cause substantial casualties of men, women and children.
Despite the best efforts of airlines and airports to screen passengers, there may never be an absolute way to prevent future atrocities. Furthermore, evidence has surfaced that plans were made to hijack tractor-trailers carrying hazardous materials, such as nuclear waste, and crash/explode these trucks in heavily populated areas to maximize injury and death to civilians.
In addition, in a somewhat different vein, every year children are severely injured/killed by handling dangerous instruments used in normal day to day activities, such as power tools, electric saws, drills, rivet guns, etc. because the adult owner of the tool either fails to keep the tools away from a child's access, whether that be momentary or ongoing.
All too often there are tragic news reports of people who are gravely injured or killed by gunshots fired by a person who is not the owner or an authorized user of the firearm. Some of these tragedies are accidental, such as when a child finds a parent's firearm and accidentally discharges it at his/herself or at friends. Other tragedies concern firearms, which are taken during burglaries, which are subsequently, used in future robberies and/or homicides. On more than one occasion, a perpetrator has been known to wrestle the gun from an officer's holster and use it against the officer.
Regardless of the specific cause, it is evident that many of these incidents could be avoided if the firearm could only be fired by the owner or other authorized user of the gun. In fact, there is in fact a current effort by citizens and lawmakers to require the inclusion of trigger locks on handguns.
U.S. Pat. No. 4,970,819 to Mayhak discloses a system for sensing the grip pattern of the hand of a potential user of a firearm and permits the firing thereof if it senses a particular grip pattern of an authorized user, which it has been programmed to recognize. The system includes grip pattern sensing means on the handgrip of the firearm, a simulated neural network memory capable of recognizing a particular grip pattern and a microprocessor for accessing the neural network to inquire whether it recognizes the grip pattern being sensed by the sensing means. The microprocessor also controls means for permitting and preventing actuation of the firing mechanism of the firearm to allow the firearm to be discharged only when the grip pattern sensed by the sensing means is that of the authorized user which the simulated neural network memory has been programmed to recognize.
According to the '819 patent, “a simulated neural network does not possess a memory in the sense that a computer has a memory. Instead, the training of a pattern recognition neural network involves repeatedly subjecting its input neurons to signals corresponding to the pattern, including variations thereof. This establishes interconnections between the input neurons, the hidden neurons and the output neuron, so that, eventually, when the trained network is subjected to a pattern signal the output is either “yes” or “no” that it is or is not the pattern it has been trained to recognize. A trained neural network will exhibit a particular pattern of interconnections between neurons therein and the pattern of connection strengths between neurons is equivalent to memory for that network” (col. 3 lines 34–48 of the '819 patent).
Furthermore, according to the '819 disclosure, once the neural network has been trained to recognize a particular pattern, it can do so even though it later is presented with small variations or incomplete information about that pattern. The neural network is thus ideally suited for recognizing a particular handgrip pattern impressed on sensing means 23 even though the authorized user may place his hand in a slightly different location or apply slightly different pressures with each grip. The neural network can be trained to take such variations into account and still distinguish the grip pattern for which it is programmed from grip patterns created by others who are not authorized to use the firearm” (from col. 3 lines 11–26 of the '819 patent).
U.S. Pat. No. 5,603,179 discloses a “safety mechanism for a firearm consisting of a specialized scanning mechanism built into the firearm's trigger. The scanner is programmed to read the unique fingerprints of a given individual. The device is also capable of holding the programmed print information for more than one person, so that multiple people would he able to use the firearm. However, usage is limited to only those persons whose handprints have been prestored in the scanner. The scanner mechanism is connected to the firearm's safety lock. The safety is prevented from being released without proper authorization from the scanner. When a person grips the weapon and places his finger on the trigger, the pressure of the finger on the trigger activates the scanner, and the scanner reads the fingerprint to determine if the scanned fingerprint matches one of the pre-stored fingerprint images. If the individual is an authorized user, the scanner transmits a signal to the safety, releasing this device and activating the firearm for use” (from abstract of the '179 patent).
U.S. Pat. No. 5,316,479 to Wong discloses a firearm training system, “which allows the measurement and display as a function of time of the hand grip force pattern applied to the grip of a firearm by a weapon hand of a shooter. This permits the detection of variations in the individual handgrip forces in the pattern during firing of the weapon. This firearm training system preferably also provides for the detection and display as a function of time of the position of the firearm trigger. The system includes separate force transducers for the side and front-to-back grip forces applied to the side surfaces and one of the front and back surfaces of the grip respectively as well as a trigger position sensor. A relative value of the hand grip forces detected by the transducers and a relative trigger position detected by the sensor are graphically displayed by the system as a function of time.
Wong discloses a method of training a shooter by determining the grip pattern of the shooter's weapon hand on a firearm by detecting a front-to-back grip force and a side grip force applied by the weapon hand and graphically displaying as a function of time a relative value of the front-to-back and side grip forces respectively. Thus, the system provides for a more effective training of a shooter, which substantially translates into cost savings in terms of training time and ammunition, especially since the firearm training system and method may effectively be used under both dry and live fire conditions” (See abstract of the '479 patent). The time period disclosed by Wong is relatively fixed, for example, 100 ms snapshot for each user training with the weapon. Wong provides feedback so that a shooter can see a “correct” way to hold the weapon and pull the trigger, as opposed to “incorrect” grips that could impair accuracy. Thus, Wong teaches a shooter how to conform to a predetermined method of holding and firing a weapon.
Accordingly, there exists a need to prevent unauthorized access to potentially dangerous instruments, which includes items that could be used as a weapon, such as aircraft and power tools from unauthorized use.